Wavelength division multiplex terminal with automatic configuration and supervision of switch connections

ABSTRACT

A wavelength division multiplexer terminal with a multiplexer arrangement with a first switching matrix, and a demultiplexer arrangement with a second switching matrix allows flexibility for connection transceivers to ports of the wavelength division multiplexer and wavelength division demultiplexer respectively. Optical monitoring receivers are connected upstream the wavelength division multiplexer and downstream the wavelength division demultiplexer for managing and supervising connections.

FIELD OF THE INVENTION

The invention refers to a wavelength division multiplex terminal withautomatic configuration and supervision of switch connections.

BACKGROUND OF THE INVENTION

Wavelength division multiplexers combine optical signals havingdifferent wavelengths and output a wavelength division multiplex signal(WDM-signal). Wavelength division demultiplexers divide a wavelengthdivision multiplex signal into a plurality of optical signals havingdifferent wavelengths. Both, multiplexers and demultiplexers, are fixedwavelength band-pass filters. Transceivers (transmitters and receivers)are connected to terminal points of said multiplexers anddemultiplexers. Each transmitter (part of the transceiver) emits andeach receiver (part of the transceiver) receives an optical signal witha certain wavelength. Each transceiver is connected to certain ports ofthe terminal, which means that new interconnections are necessary if thenumber of transceivers is upgraded or new connections between ports andreceivers are necessary. Several transceivers can be attached as frontends to an electrical switching matrix.

OBJECTS AND SUMMARY OF THE INVENTION

It is an object of the invention to improve the flexibility of awavelength division multiplex terminal and to supervise ports and switchconnections.

These problems are solved by the features described in claim 1.

Additional advantageously features are described in dependent claims.

For reasons of flexibility transceivers are connected via a firstswitching matrix with inputs of a wavelength division multiplexer andvia a second switching matrix with outputs of a wavelength divisiondemultiplexer. For supervision of the connections it is advantageouslyto connect optical monitoring receivers to inputs of the wavelengthdivision multiplexer respectively outputs of a first switch matrix toreceive identification signals for routing transmitter signals toselected ports of the wavelength division multiplexer. An equipmentmanagement unit receiving identification information from the opticalmonitoring receivers identifications the switch matrix. The sameidentification signals or (similar) supervision signals can be used tosupervise the switch connections. If the output signal frequencies ofthe transceivers are tuneable maximum flexibility of connections isensured.

A complete duplex connection can be supervised if the transmitting andthe receiving side are monitored. The second switching matrix assignedto the wavelength division demultiplexer can be managed either byidentification signals output from the associated transceivers or byreceived identification signals emitted from a remote terminal. In thiscase the identification signals are monitored in adown-stream/demultiplexing path, preferable downstream at the outputs ofthe second switch matrix.

For design reasons an interleaver and a deinterleaver can be used in themultiplexing respectively demultiplexing arrangement. Then multiplexersand demultiplexers with broader filters can be used.

Power splitters and power combiners or further switch matrices can beused at the inputs and outputs of multiplexers and demultiplexers,respectively, in order to realize bidirectional steering of transpondersignals and supervision of their interconnections to the terminals.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be explained in more detail in conjunction with theappended drawings, wherein:

FIG. 1 shows a simplified block diagram of a preferred first embodimentof the invention,

FIG. 2 shows a second block diagram of a second WDM terminal comprisingan interleaver and a deinterleaver,

FIG. 3 shows a block diagram of a third WDM terminal comprisingwavelength selective switches,

FIG. 4 shows a third block diagram of an terminal arrangement comprisinga plurality of wavelength division multiplex terminals,

FIG. 5 shows a block diagram of this terminal arrangement comprising animproved photonic switching ability, and

FIG. 6 shows a block diagram of an second terminal arrangementcomprising multiplexer and demultiplexer switching matrices.

DESCRIPTION OF PREFERRED EMBODIMENTS

The simplified block diagram of FIG. 1 illustrates a first wavelengthdivision multiplex terminal (WDM terminal) WDT1 with a multiplexingarrangement 4, 3 j, 2 (j=1−N) in an upstream path and a demultiplexingarrangement 7, 8, 9 j in a downstream path. Ordinary elements used inthe terminal like amplifiers, dispersion compensators are notillustrated.

The multiplexing arrangement comprises a first switching matrix 4, whoseinput ports 4I_1-4I_N are connected to outputs 5A_1-5A_N of Ntransceivers 5_1-5_N (or less or even more transceivers according to theexpansion stage). Output ports 4A_1-4A_N of the first switching matrixare connected to input terminals 2I_1-2I_N of a wavelength divisionmultiplexer 2 (MUX), which combines optical input signals to a WDMsignal WDST.

One or several first identification signals CT1-CTN areoutput-controlled by an equipment management unit 10 by transceivercontrol signals TCS—from one or several transceivers 5_1-5_N in a formof modulated light e.g. with on-off keying.

Optical monitoring receivers 31-3N are connected (via not shownsplitters) to the output ports 4A_1-4A_N of the first switching matrix 4via splitters (not shown) or—physically the same—to input terminals2I_1-2I_N of the wavelength division multiplexer 2.

The monitoring receivers operate essentially wavelength independent, sothat each first identification signal output by a transceiver isreceived by one of the monitoring receivers according to a switchposition of the first switching matrix 4. This monitoring receiver 3 j,(j=1−N) receives the first identification signal CTj (j=1−N) andconverts it into first identification information ITj (in the simplestcase into an electrical signal without changing the information), whichis fed to the equipment management unit 10. The first identificationsignal CTj and the identification information ITj includes an equipmentnumber of the transceiver, the shelf and slot position, the frequency ofthe transceiver or equivalent information. It can e.g. also contain therequired input port of the wavelength division multiplexer 2 or thecorrect switch position.

The management unit 10 converts the first identification signalrespectively the first identification information first into portinformation and than into a correct switch position, configures theconnections of the first switching matrix by transceiver control signalsTCS and routes the transceiver signals to the associated input terminalsof the wave-length division multiplexer 2 (and as will be describedlater, the received signals from the demultiplexer to the transceiver).It is always necessary that an optical signal with a certain wavelengthis input at the associated input of the multiplexer 2.

After an appropriate setting of the first switching matrix 4 theequipment management unit 10 supervises the connections of the firstswitching matrix 4 by monitoring additional identification signals CTjor corresponding supervising signals. This can be done step by stepafter each setting. The first WDM terminal WDT1 is bidirectionalconnected to a remote WDM terminal WDT2, which transmits a second WDMsignal WDSR to the demultiplexing arrangement of the first WDM terminalWDT1.

The demultiplexing arrangement comprises a wavelength divisiondemultiplexer 7 (DEMUX), which receives at an input 6 an opticalWDM-signal WDSR. The outputs 7A_1-7A_N of the demultiplexer 7 areindividually connected to input ports 8I_1-8I_N of a second switchmatrix 8. Output ports 8A_1-8A_N of the second switch matrix 8 areindividually connected to inputs 5I_1-5I_N of the transceivers 51-5N.

The switching matrices 4 and 8 can also be realized within one singleswitching matrix with the double amount of input and output ports.

There are two possibilities of controlling the second switching matrix8.

-   -   The second switching matrix 8, which is routing the received        signals, is directly controlled according the first        identification signals CTj emitted by the transceivers.    -   The second switching matrix 8 is controlled according the        received second identification signals CRj emitted from the        second WDM terminal WDT2.

In a first embodiment, the equipment management unit 10 of the WDMterminal WDT1 controls the first switching matrix 4 and the secondswitching matrix 8 according to the first identification signals CTj,which are converted into matrix control signals MCS and fed to theswitching matrices 4 and 8.

According to a second embodiment, the second switching matrix 8 iscontrolled according to second identification signals CRj emitted from atransceiver of the second wavelength division terminal WDT2. Aftersetting the switch position of the first switching matrix 4, theidentification signals CTj can be transmitted to the remote wavelengthdivision terminal WDT2 via the data channel or via a separateinformation path (e.g. optical supervisory channel).

The second identification signals CR1-CRN are received by the second WDMterminal WDT2. The received identification signals CRj (and supervisionsignals) are converted into identification information IRj and used forsetting the sec- and switching matrix 8 and/or supervision of theconnections. In this case both management units and both identificationsignals are involved to build up the bidirectional connection. Thereforethe managements units of both terminals are bidirectional connected witheach other to exchange control information.

There are several additional variations and possibilities to supervisethe function of the demultiplexing arrangement:

-   -   The output ports of the demultiplexer 7 are supervised.    -   The output ports of the second switching matrix 8 are        supervised.    -   Only the presence of a signal, that means the correct        wavelength, is supervised by the transceivers or by monitoring        receivers.    -   The second switching matrices 4 and 8 are supervised by the        management unit 10 varying (modulating) the attenuation of        variable optical attenuators, VOAs, with a further        identification signal or even by on-off-switching. Therefore it        is advantageously to have variable optical attenuators, VOAs, at        the inputs especially of the sec- and switching matrix or even        having VOAs integrated in the switching matrices. The        information imposed onto the modulation can be derived from the        identification signals CT1-CTN or CR1-CRN or can be generated by        the management unit.    -   The supervision can also be done by the transceivers (at least        the optical-electrical converters can be used).

Additional monitoring receivers 9 j, j=1−N can be connected to the inputports of the second switching matrix 8. But then is a supervision of thesecond switching matrix 8 not possible.

In a preferred embodiment of the invention, the additional monitoringreceivers 9 j-9N are connected to output ports 8A_1-8A_N of the secondswitching matrix 8. The second identification signals CRj are convertedinto “second identification information” IRj and also fed to themanagement unit 10.

For the management of the second switching matrix 8 by the secondidentification signals CRj it is necessary that the systems areidentical or have sufficient information about the other WDM terminal.

Only the supervision of the received second identification signals CRj,which contain information from the signal emitting transceivers of thesecond multiplexer terminals WDT2 (at least the wavelength), at theoutput ports of the second switching matrix 8 ensures that theconnections in both WDM terminals WDT1 and WDT2 are correct. Of course,the presence and power level of the transmitted and received signals arealso monitored.

FIG. 2 shows simplified block diagram of a second embodiment of awavelength division terminal WDT2 comprising an interleaver 11 and adeinterleaver 12.

The multiplexing arrangement comprises wavelength division multiplexers21-2M, M=2, 4, 6, . . . whose outputs are connected to M inputs of theinterleaver 11.

The demultiplexer arrangement comprises wavelength divisiondemultiplexers 71-7M, M=2, 4, 6, . . . whose inputs are connected to Moutputs of the deinterleaver 12.

This embodiment has the advantage that multiplexers and demultiplexerswith broader filters can be used.

The management unit is not shown, but its function is identical with thefunction of the embodiment described before.

FIG. 3 shows a simplified block diagram of a third embodiment of awavelength division terminal WDT3 comprising including wavelengthselective switches (WSS) 24 and 78, each WSS is replacing amultiplexer/demultiplexer and a switching matrix. The function isidentically. The disadvantage of the known WSSs is that there is nopossibility to branch of signals between the “switching matrix” and the“multiplexer”. Therefore for the monitors have to be arrayed at theinputs of the WSS 24. The function of the WSS 24 in theupstream/multiplexing path can only be checked indirectly bysupervising—e.g. in a loop—the received identification signals CRj.Another possibility is a monitoring receiver with spectrum analyserfeatures connected to an output of the WSS 24.

FIG. 4 shows a simplified block diagram of a terminal arrangement TA1comprising a plurality of first wavelength division multiplex terminalsWDT1_1-WDT1_K with additional switching capability between the terminalsin a PXC (Photonic Cross Connect) layer enabled by first and secondwavelength selective switches 15_1-15_K and 16_1-16_K respectively.

The WDM terminals comprise, as described before, in their multiplexingpaths a first switching matrix 4_1-4_K, a multiplexer 2_1-2_K, and inaddition a first wavelength selective PXC (Photonic X (X=Cross) Connect)switch 15_1-15_K. Added signals can be fed from outputs of transceivers5_1-5_N via additional first switches/splitters 13_1-13_N to firstswitching matrices 4_1-4_K.

The WDM terminals comprise in their demultiplexing paths a secondwavelength selective PXC switch 16_1-16_K, a demultiplexer 7_1-7_K, anda second switching matrix 8_1-8_K. Dropped signals are fed from the PXCWS switches 16_1-16_K via demultiplexers 7_1-7_K and via secondswitching matrices 8_1-8_K and second switches/combiners 14_1-14_N toinputs of the transceivers 5_1-5_N (a variable number of transceivers,in this example N transceivers, can be connected to a variable number ofthe terminals). The PCX WSS switches can be replaced bysplitters/combiners.

The first WDM terminals WDT1_1-WDT1_K of the shown arrangement areconnected via the PXC WSS 15_1-15_K and 16_1-16_K with remote WDMterminals WDT2_1-WDT2_K. The signals of a WDM signal, e.g. WDST1, outputfrom a multiplexer 2_1 are combined with other signals of the other WDMsignals WDST2-WDSTK and transmitted as a WDM signal WDST_1. All togetherthe WDM signals WDST_1-WDST_K are transmitted via outputs 1P_1-1P_K ofthe first PCX WS switches 15_1-15_K. Each WDM signal WDRS_1-WDRS_K isreceived via inputs 6P_1-6P_K of second PCX WS switches 16_1-16_K (or asplitter/combiner instead of a switch). Selected and dropped WDM signalsWDSR1-WDSRK are fed to allocated demultiplexers 7_1-7-K. Further outputsof the PXC WSSs 16_1-16_K in the demultiplexing paths 16_1-16_K areconnected via connections (e.g. fibers) PX1K, PXK1, . . . to allocatedinputs of the first PXC WS switches 15_1-15_K in the multiplexing pathsto enable photonic cross connections (only two connections areillustrated).

The multiplexers and demultiplexers in an add drop logic ADL areconnected to the switching matrices in a way described above, butswitches/splitters and switches/combiners are inserted between theswitching matrices and the transceivers.

Regarding the first WDM terminal WDT1_1 an input of at least one firstswitch/splitter 13_1 is connected to the output 5A_1 of the firsttransceiver 5_1, and an output of at least one second switch/combiner14_1 is connected to the input 5I_1 of this transceiver. Additionaloutputs of the first switches/splitters 13_1 are connected to inputports of the first switching matrices 4_1-4_K of the other first WDTsWDT1_2-WDT1_K (or of only a limited number of them, e.g. 2 or 3); andadditional inputs of the second switches/combiners 14_1-14_N areconnected to output ports of the second switching matrices 8_1-8_K ofthe other first WDTs WDT1_2-WDT1_K (or of only a limited number of them,e.g. 2 or 3). For a sufficient protection it is advantageously if allinputs and all outputs of all transceivers 5_1-5_N are connected viafirst switches/splitters 13_1-13_N or second switches/combiners14_1-14_N to at least first WDM terminals WDT1_1-WDT1_K.

The first switch 13_1 and the second switch 14_1 can also be combined inone switch matrix.

Of course, the terminal arrangement can also be assembled by theembodiments of FIG. 2 or FIG. 3.

The management unit 10 again is not shown, but the function is similarwith the embodiment described before, but connectivity of more than oneWD terminal can be managed and supervised.

FIG. 5 shows the arrangement with an extended photonic cross connectPXC. Additional splitters PS1_1-PSK_K are inserted between the outputsof the multiplexers 2_1-2_K (or interleavers 11_1-11_K) and the WSSs15_1-15. At least one output of the additional splitters is connected toat least an input of a second multiplexer. Additional combinersPS2_1-PS2_K are inserted between the WSSs 16_1-16_K and thedemultiplexers 7_1-7_K (or the deinterleavers 12_1-12_K). At least oneinputs of the additional combiners is connected to an output of an otherdemultiplexer.

This arrangement enables cross connections between output WDM signalsvia connections CT1K, CTK1, . . . or between signals output from theWSSs 16_1-16_K via connections CR1K, CRK1, while the PXC connectionsPX1K-PXK1 described before allow PXC connections between received andtransmitted signals.

FIG. 6 shows a simplified block diagram of second terminal arrangementTA2 with restricted switching capability. A first multiplexer matrix4M_1 is connecting an output 5A_1 of the first transceiver 5_1 to allfirst inputs 2I_11-2I_1K of the multiplexers 2_1-2_K; and the outputs ofthe other transceivers 5_2-5_N are connected in a corresponding way viamultiplexer matrices 4M_2 (not shown)-4M_K to further inputs of themultiplexers 2_1-2_K. The multiplexer matrix 4M_1 needs only N inputsand N×K outputs (only the transceivers 5_1 and 5_N and their connectionsare shown for reasons of clarity). In a corresponding manner are allfirst outputs 7A_11-7A_1K of the demultiplexers 7_1-7_K connectable viademultiplexer matrices 8M_1-8M_K to the input of the first transceiver5_1; and in a corresponding way all the other outputs of thedemultiplexers 7_1-7_K to the inputs of the other transceivers.

The switches of the multiplexer matrix and the demultiplexer matrixallocated to a WDM terminal can be also arranged in a single chip; alsoall switches can be designed in a larger chip and allocated to e.g. aconnection board.

If the output and input wavelength of the transceivers are selectable ortuneable, this is a low cost but embodiment with good switchingpossibilities.

Of course a common switching matrix which allows connections between allinputs and all outputs may be available in the future and can replacethe shown matrices. This common switching matrix will also replace thecombination of splitters 13_1-13_N, 14_1-14_N and matrices 4_1_4_K,8_1-8_K shown in FIG. 4.

A combination with a photonic cross connect as described before is alsopossible.

The management unit 10 again is not shown, but the function is similarwith the embodiment described before, but connectivity of more than oneterminal can be managed and super-wised.

REFERENCE SIGNS

-   WDT1 first wavelength division multiplex terminal-   WDT2 remote second wavelength division multiplex terminal-   WDT1_1-WDT1_K first and at least second wavelength di vision    terminal-   WDT2_1-WDT2_K first and at least second remote wave length division    terminal-   WDST transmitted WDM signal-   WDSR received WDM signal-   1 multiplexer output-   1_1-1_K outputs of the WDT1s-   2 wavelength division multiplexer-   2I_1-2I_N inputs of the wavelength division multiplexer-   21-2M wavelength division multiplexer-   M number of interleaver outputs-   2_1-2_K first to K^(th) multiplexer in K WDT1s-   3 j monitoring receivers-   3 j_1-3 j_K monitoring receivers-   4 first switching matrix-   4I_1-4I_N input ports of the first switching matrix-   4A_1-4A_N output ports of the first switching matrix-   4_1-4_K first switching matrices-   4D_1-4D_N multiplexer switching matrix-   5 transceivers-   N number of channels-   5I_1-5I_N inputs of the transceivers-   5A_1-5A_N outputs of the transceivers-   6 demultiplexer input-   6-1-6_K inputs of the WDT1s-   K number of WDT1s-   7 wavelength division demultiplexer-   7A_1-7A_N outputs of the wavelength division demultiplexer-   71-7M wavelength division demultiplexer-   8 second switching matrix-   8I_1-8I_N input ports of the second switching matrix-   8A_1-8A_N output ports of the second switching matrix-   8_1-8_K second switching matrices-   8M_1-8M_N demultiplexer switching matrix-   9 j additional monitoring receivers-   9 j_1-9 j_K additional monitoring receivers-   10 equipment managing unit-   MCS matrix control signal-   TCS transceiver control signal-   11 interleaver-   12 deinterleaver-   11_1-11_K interleaver-   12_1-12_K deinterleaver-   13_1-13_N switches/splitters-   14_1-14_N switches/combiners-   15_1-15_K first PXC WSS (transmitter)-   16_1-16_K second PXC WSS (receiver)-   PXC photonic cross connect-   ADL add-drop logic-   CT1-CTN transmitted identification signal-   CR1-CRN received identification signal-   IT1-ITN transmitted identification information-   IR1-IRN received identification information-   PS1_1 PXC splitter-   PS2_1 PXC combiner-   PX1K WSS connection 1-K-   CR1K combiner connection 1-K-   CT1K splitter connection 1-K-   PS2_1 splitter in PXC

1. A wavelength division multiplex terminal (WDT1) for automaticconfiguration and supervision of switch connections, the wavelengthdivision multiplex terminal (WDT1) containing a multiplexer arrangement(4, 3j, 2) receiving signals from a plurality of transceivers (5_1-5_N)and transmitting a first wavelength division multiplex (WDM) signal(WDST), the terminal (WD1) comprising a first switching matrix (4),whose input ports (4I_1-4I_N) are connectable to outputs (51_A-5N_A) ofthe transceivers (5_1-5_N), a wavelength division multiplexer (2), whoseinputs (2I_1-2I_N) are connectable to output ports (4A_1-4A_N) of thefirst switching matrix (4) a plurality of optical monitoring receivers(31-3N), each optical monitoring receiver connected to an input port(2_1-2_N) or output port (4A_1-4A_N) of said first switching matrix (4)respectively, the optical monitoring receivers (31-3N) being designedfor receiving first identification signals (CT1-CTN) output from thetransceivers (5_1-5_N) and outputting first identification information(IT1-ITN), a management unit (10), receiving said first identificationinformation (CT1-CTN) from the optical monitoring receivers (31-3N), themanagenent unit (10) being designed for connecting outputs (5A_1-5A_N)of the transceivers (5_1-5_N) via the first switching matrix (4) to theinputs (2_1-2_N) of the wavelength division multiplexer (2) according tothe first identification signals (CT1-CTN) and/or supervising theconnections of the multiplexer arrangement (4, 3j, 2) according to firstsupervising signals or the first identification signals (CT1-CTN) outputfrom the transceiver (5_1-5_N).
 2. The terminal according to claim 1,comprising a demultiplexer arrangement (7, 8, 9j) including a wavelengthdivision demultiplexer (7) for receiving a second wavelength divisionmultiplex signal (WDSR) from a remote wavelength division multiplexterminal (WDT2), a second switching matrix (8), whose input ports(8I_1-8I_N) are connected to outputs (8A_1-8A_N) of said wavelengthdivision demultiplexer (8), and whose output ports (8I_1-8I_N) areconnectable to inputs (5I_1-5I_N) of the transceivers (5_1-5_N), themanagement unit (10) being additional designed for controlling and/orsupervising the connections of the demultiplexer arrangement accordingto the first identification signals (CT1-CTN) or the first supervisingsignals output by the transceivers (5_1-5_N).
 3. The terminal accordingto claim 1, comprising a demultiplexer arrangement (7, 8, 9j) includinga wavelength division demultiplexer (7) for receiving a secondwavelength division multiplex signal (WDSR) from a remote wavelengthdivision terminal (WDT2), a second switching matrix (8), whose inputports (8I_1-8I_N) are connected to outputs (7A_1-7A_N) of saidwavelength division demultiplexer (7), and whose output ports(8A_1-8A_N) are connectable to inputs (5I_1-5I_N) of the transceivers(5_1-5_N), additional optical monitoring receivers (91-9N) connected tooutput ports (8A_1-8A_N) of the second switching matrix (8) designed forreceiving second identification signals (CR1-CRN) from the remotewavelength division terminal (WDT2), and outputting receivedidentification information (IR1-IRN), the management system (10) beingadditionally designed for controlling the connections of thedemultiplexer arrangement (7, 8, 9j) according to the received secondidentification signals (CR1-CRN) and/or for supervising said connectionsaccording to the received second identification signals (CR1-CRN)signals or second supervising signals emitted from remote secondwavelength division terminal (WDT2).
 4. The terminal according to claim1, comprising a demultiplexer arrangement (7, 8, 9 j) including awavelenght division demultiplexer (7) for receiving a second wavelenghtdivision multiplex signal (WDSR), a second switching matrix (8), whoseinput ports (8I_1-8I_N) are connected to outputs (7A_1-7A_N) of saidwavelength division demultiplexer (7) and whose output ports (8A_1-8A_N) are connectable to inputs (5I_1-5I_N) of the transceivers(5_1-5_N), additional optical monitoring receivers (91-9N) connected toinput ports (8I_1-81_N) of the second switching matrix (8) designed forreceiving second identification signals (CR1-CRN) from the remotewavelength division terminal (WDT2) and outputting receivedidentification information (IR1-IRN), and the management unit (10) beingadditionally designed for controlling the second switching matrix (8)according to received second identification signals (CR1-CRN) and/or forsupervising the second switching matrix (8) according to the secondidentification signals (CR1-CRN) or second supervising signals emittedfrom the remote second wavelength division terminal (WDT2).
 5. Theterminal according to one of the claims 2-4, comprising the opticalmonitoring receivers (31-3N; 91-9N) and the management unit (10) beingadditionally designed for supervising presence or power levels ofoptical signals emitted from the transceivers (5_1-5_N).
 6. The terminalaccording to one of the claims 2-5, comprising said switching matrices(4; 8) capable of varying the attenuation controlled by the managementunit (10).
 7. A WDM terminal (WDT2) according to one of the claims 2-6,comprising an interleaver (11), which first input is connected to anoutput of a first wavelength division multiplexer (21) and which atleast second input (2M) is connected to an output of an at least secondwavelength division multiplexer (2M), and/or a deinterleaver (12), whichfirst output is connected to an input of a first wavelength divisiondemultiplexer (71) and which at least second output is connected to aninput of at least a second wavelength division demultiplexer (7M). 8.The terminal according to one of the claims 1-7, characterized in thatthe optical monitoring receivers (31-3N) are connected to output portsof the first switching matrix (2).
 9. A WDM terminal (WDT3) according toone of the claims 1-3, 5-7, characterized by a first wavelengthsselective switch (24) replacing the first switching matrix (4) incombination with the wavelength division multiplexer (2), wherein theoptical monitors (3j) are connected to input ports (4I_1-4I_N) of saidfirst wavelengths selective switch (24) and/or a second wavelengthselective switch (78) replacing the wavelength division demultiplexer(2) in combination with the second switching matrix (8), and themonitoring receivers (3j) are connected to inputs (4I_1-4I_N) of thefirst wavelengths selective switch (24).
 10. A first terminalarrangement (TA1) comprising a plurality of wavelength divisionmultiplex terminals (WDT1_1-WDT1_K) according to one of the claims 1-9,characterized by first optical switches/splitters (13_1-13_N), whoseinputs are connectable to outputs of the transceivers (5_1-5_N)respectively, and whose outputs are connectable to input ports of thefirst switching matrices (4_1-4_K) respectively; and second opticalswitches/combiners (14_1-14_N), whose inputs are connected to outputports of the second switching matrices (8_1-8_k; respectively, and whoseoutputs are each connectable each to inputs of the transceivers(5_1-5_N) respectively.
 11. The terminal arrangement (TA1) according toclaim 10, characterized in that a photonic cross connect (PXC) isinserted between inputs (1P_1-1P_K) and outputs (6P_1-6P_K) of thewavelength division multiplex terminals (WDT1_1-WDT1_K) and themultiplexers (2_1-2_K) and demultiplexers (7_1-7_KP respectively toallow photonic cross connect functionality between different wavelengthdivision multiplex terminals (WDT1_1-WDT1_K).
 12. The terminalarrangement (TA1) according to claim 11, characterized by the photoniccross connect (PXC) including first wavelength selective PXC (PhotonicCross Connect) switches (15_1-15_K) inserted in multiplexing paths ofthe WDM terminals (WDT1_1-WDT1_K) outputting first wavelength divisionmultiplex signals (WDST_1-WDST_K), and including second wavelengthselective PXC switches (16_1-16_K) inserted in demultiplexing paths ofthe WDM terminals (WDT1_1-WDT1_K) receiving second wavelength divisionmultiplex signals (WDSR_1-WDSR_K), of which one output is fed to anallocated demultiplexer (7_1-7_K) dropping a WDM signal (WDSR1-WDSRK),and of which other outputs are connected to inputs of the other firstwavelength selective PXC switches (15_1-15_K).
 13. The terminalarrangement (TA1) according to claim 11 or 12, characterized by thephotonic cross connect (PXC) including PXC splitters (PS1_1-PS1_K)inserted between the multiplexers (2_1-2_K) and the first wavelengthselective PXC switches (15_1-15_K) having additional outputs connectedvia connections (CT1, CTK) to inputs of the other first wavelengthselective PXC switches (15_1-15_K), and including PXC combiners(PS2_1-PS2_K) inserted between the second wavelength selective PXCswitches (16_1-16_K) and the demultiplexers (7_1-7_K) having additionalinputs connected via connections (CR1, CRK) to inputs of the other firstwavelength selective PXC switches (15_1-15_K),
 14. The terminalarrangement (TA1) according to claim 12, characterized in that the firstwavelength selective PXC (Photonic Cross Connect) switches (15_1-15_K)or the second wavelength PXC selective switches (16_1-15_K) are replacedby combiners or splitters respectively.
 15. A second terminalarrangenent (TA2) for automatic configuration and supervision of switchconnections comprising a plurality of multiplexer arrangements (4M_1,2_1-4M_K, 2_K), each receiving signals from a plurality of transceivers(5_1-5_N) and transmitting a first WDM signals (WDST_1-WDST_K) andcomprising a plurality of demultiplexer arrangements (7_1, 8M_1-7_K,8M_K), each receiving a second WDM signal (WDSR_1-WDSR_K) anddistributing received signals to the transceivers (5_1-5_N), comprisingmultiplexer switching matrices (4M_1-4M_K), whose input ports (8I_11, .. . ) are connectable to allocated outputs (5A_1-5A_N) of thetransceivers (5_1-5_N), and whose output ports are connectable toallocated inputs (2I_11-2I_NK) of wavelength division multip.exers(2_1-2_K), wherein the multiplexer switching matrices (4M_1-4M_K) enableconnection between tranceiver outputs (5A_1-5A_N) and an allocated input(2I_11-2I_NK) of said wavelength division multiplexers (2_1-2_K), thewavelength division multiplexers (2_1-2_K) outputting the first WDMsignals (WDST_1-WDST_K), a plurality of optical monitoring receivers(3j_1-3j_K), each connected to an input (2I_11-2I_NK) of said wavelengthdivision multiplexers (2_1-2_K) being designed for receivingidentification signals (CT1_1-CTN_K) from the transceivers (5_1-5_N) andoutputting identification information (IT_1-IT_N); demultiplexerswitching matrices (8M_1-8M_K), whose input ports (8I_11, . . . ) areconnected to allocated outputs (7A_11, . . . ) of wavelength divisiondemultiplexers (7_1-7_K), said wavelength division demultiplexers(7_1-7_K) receiving second WDM signals (WDSR_1-WDSR_K), and whose outputports (8A_11, . . . ) are connectable to allocated inputs (5I_1-5I_N) ofthe of the transceivers (5_1-5_N), wherein the demultiplexer switchingmatrices (8M_1-8M_K) enable connection between each tranceiver input andan allocated output (7A_11, . . . ) of all said wavelength divisiondemultiplexers (7_1-7_K), optical monitoring receivers (3j_1-3j_K;j=1-N), each being connected to allocated outputs (7A_11-7A_NK) of thewavelength division demultiplexers (7_1-7_K) and outputtingidentification information (IT1-ITN), a management unit (10), receivingsaid identification information (IT1-ITN) from the optical monitoringreceivers (3j_1-3j_K), the management unit (10) being designed forconnecting outputs (5A_1-5A_N) of the transceivers (51-5N) via themultiplexer switching matrices (4M_1-4M_K) to the inputs of thewavelength division multiplexers (2_1-2_K)) according to theidentification signals (CTj_1-CTj_N) and/or supervising the connectionsaccording to supervising signals or the identification signals(CTj_1-CTj_N) output from the transceiver (5_1-5_N).
 16. The secondarrangement (TA1) according to claim 15, comprising additional opticalmonitoring receivers (91_1-9N_K) connected to output ports (8A_1-8A_N)of the demultiplexer switching matrices (8M_1-8M_K) receiving secondidentification signals (CR1-CRN) from the remote wavelength divisionterminal (WDT2), and the management system (10) being additionallydesigned for controlling and/or supervising the demultiplexer matrices(8M_1-8M_K) according to received identification signals (CR1_1-CRN_K)or supervising signals emitted from the remote second wavelengthdivision terminal (WDT2).
 17. The second arrangement according to claim15 or 16, characterized in that at least one multiplexer switchingmatrix (4M_1-4M_K) and at least one demultiplexer switching matrix(8M_1-8M_K) are combined to one switching matrix.
 18. The terminalarrangement (TA1) according to one of the claims 15-17, characterized inthat a photonic cross connect (PXC) is inserted between inputs(1P_1-1P_K) and outputs (6P_1-6P_K) of the wavelength division multiplexterminals (WDT1_1-WDT1_K) and the multiplexers (2_1-2_K) anddemultiplexers (7_1-7_K) respectively to allow photonic cross connectfunctionality between different wavelength division multiplex terminals(WDT1_1-WDT1_K).